/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.eagle.alert.engine.sorter;

/**
 * The time clock per stream should be thread-safe between getTime and moveForward.
 * By default, we currently simple support event timestamp now.
 */
public interface StreamTimeClock {
    /**
     * Get stream id.
     *
     * @return stream id
     */
    String getStreamId();

    /**
     * Get current time.
     *
     * @return current timestamp value
     */
    long getTime();

    /**
     * @param timestamp move forward current time to given timestamp.
     */
    void moveForward(long timestamp);
}